Getting a rebuilt engine to start

[Do Little]

So I took my engine apart because I was dumb. Just the top half and side covers, didn't crack the bottom case. Got it all back together, and now I'm having trouble getting it to start. This is my first engine diss/reassembley, but I'm fairly mechanically inclined.. Is there anything special I'm supposed to do after I put it together to get it to crank and fire properly? All I did was fill it with oil and try to start it with starting fluid.

I'm thinking it could be a bad battery not having enough power to crank it over, but I just wanted to double check. It'll cycle 2-3 times then stop, then if I hit the start button it does the same thing again. And if I crank it with the whatever its called on the side that lets you manually crank it with a wrench, it gets tighter when the pistons are towards the top. Could I have something torqued to tight or out of whack?

Thanks.

[7981GS]

How did you align the timing marks and the cam sprockets?

Daniel

[bwringer]

Sounds like your timing may not have been set right. Your shop manual will have clear, precise instructions. If you put it together without setting the timing, then it's quite likely you bent some valves.

But back up: what the heck are you hoping to learn or accomplish with the starting fluid?

Starting fluid is a great way to destroy your engine, and possibly your bike, your house, and yourself.

Why? What's the point? There is no point. There's nothing useful you can learn from using this crap, and you're taking a huge risk. Starting fluid does a very efficient job of removing any lubrication from the cylinders, it rots your brain, and it obviously is extremely flammable and risky stuff to spray around willy-nilly.

Take the starting fluid to the nearest toxic chemical disposal facility. It has no use in your garage.

[hjfisk]

Sounds like your timing may not have been set right. Your shop manual will have clear, precise instructions. If you put it together without setting the timing, then it's quite likely you bent some valves.

But back up: what the heck are you hoping to learn or accomplish with the starting fluid?

Starting fluid is a great way to destroy your engine, and possibly your bike, your house, and yourself.

Why? What's the point? There is no point. There's nothing useful you can learn from using this crap, and you're taking a huge risk. Starting fluid does a very efficient job of removing any lubrication from the cylinders, it rots your brain, and it obviously is extremely flammable and risky stuff to spray around willy-nilly.

Take the starting fluid to the nearest toxic chemical disposal facility. It has no use in your garage.

Cannot agree more, ditch the starting fluid. If you did it right it will start almost immediately once it gets fuel. Back up and go over all your timing marks and MAKE SURE that they are correct or all you have done will be for nothing.SAY NO TO STARTING FLUID

[Do Little]

I believe I have the timing right, I followed the manual. How tight should the timing chain be? It didn't specify that in the manual, and I noticed as I tightened down the 2nd camshaft that it wanted to rotate backwards and loosen the chain. Should it be tight or have a little slack between the 2 cam shafts? Or do I just make sure the timing marks are correct and it will set it's own tension? I also noticed that it pushed air out the carbs when I cycled it with the wrench. I know the basics of how an engine works, but I'm still new to the inner workings and specifics of engines.

I was using starting fluid because I didn't have any gas, and I just wanted to see if it would fire at all before I filled up the tank and hooked it all up. Starting fluid is a tradition around here, coming from a family working on old tractors and machinery that was constantly left sitting around for long periods of time.

[bwringer]

You'll need to get a manual and follow the instructions exactly.

There is a precise procedure for setting the timing -- it involves setting the crank at a certain precise point, placing the cam chain precisely at a certain point on the sprockets, and carefully counting a certain number of pins in the cam chain between the sprockets.

The details of this procedure are a little different for every GS engine, so no one is going to post the exact procedure here. Check Basscliff's site for sources for shop manuals.

[Do Little]

I have a manual, both manuals actually, and I followed them. I'll check the timing and the manuals the next time I work on it. Seems to be what everybody is suggesting.

[chef1366]

It should get tighter with the compression. Take out the spark plugs and see if you are getting a push of air out of each spark plug hole on each stroke and if the starter will turn it with no compression.
I hope you didn't fold a ring.

[Do Little]

I did do that, and it was easier to crank with the spark plugs out. I guess that makes sense now that you mention it. Like I said, I'm new to this and I'd never really cranked the engine manually before and just wanted to make sure. I might just take it to the mechanic to get it ready for the road, it's already going for carb adjusting. I'm just not profecient enough with a voltmeter to figure out if it's electrical or if there's more to it than just a battery. That, and I'm just ready to get it on the road and it's hard telling how long it would take me to get it road worthy.